Influence of Design Practices and Climate Change Effects on the Seismic Fragility and Life-Cycle Cost of Highway Bridges

Over the past several decades seismic design practices of highway bridges have undergone a considerable change from typical non-seismic design to adoption of modern ductile detailing principles. Despite such advances in structural design, bridge structures around the globe continue to be exposed to deteriorating agents from the surrounding atmosphere. The ill effects of these environmental stressors are likely to be further compounded from potential climate change scenarios as the bridge continues to age along the service life. For bridges across different design era that are exposed to unfavorable environmental conditions, climate change settings, and simultaneously situated in moderate to high seismic zones, a renewed systematic assessment of seismic fragility and life-cycle cost is required. These estimates will facilitate informed decision making and efficient channeling of monetary resources for structural upgrade and repair. In this context, the present study proposes a novel framework to compare the lifetime seismic losses of highway bridges considering earthquakes hazard, seismic design era, aging effects, and global warming due to climate change. The proposed framework is demonstrated on a non-seismically designed case-study multi- span continuous {MSC) concrete girder bridges located within Central and Southeastern United States. This bridge comprises of multiple bridge components that are also prone to the adverse effects of environmental degradation. Results reveal substantial deviation in lifetime seismic losses and fragility when expected future climate changes are neglected.